Hi Colin,
I bought a 1997 Galaxy a few weeks ago, I am 99% sure that it is a 1" headset, I can go and have a look at mine and try and confirm. The stem is 22.2mm, I don't know if this indicates that the headset is 1".
All I can tell you with BBs is that I replaced mine - original triple chainset - and it's a 117mm spindle, so I guess that you'l need something narrower.
is yours a 'World Tour 97' as indicated by a decal on the seattube? I don't that this means anything, the frame seems the same as any other Galaxy, bar minor yearly changes.
Kevin